Coexistence of multiple sclerosis and ankylosing spondylitis: Report of four cases from Russia and review of the literature.

Multiple sclerosis is a chronic demyelinating disorder of the central nervous system. There are many cases of multiple sclerosis - like syndrome and demyelinating disorders in systemic lupus erythematosus, Sjogren disease, Behcet disease and other autoimmune conditions. Coexistence of ankylosing spondylitis and multiple sclerosis usually is rare but in this article we report 4 Russian patients with concomitant multiple sclerosis and ankylosing spondylitis diseases.